From 0f5016a79341fb58c4f589e65631a72f71996720 Mon Sep 17 00:00:00 2001
From: Sean Lilley <lilleyse@gmail.com>
Date: Tue, 18 Oct 2016 11:26:37 -0400
Subject: [PATCH] Support both === and !==

---
 Source/Scene/Expression.js    | 21 +++++++++++++--
 Specs/Scene/ExpressionSpec.js | 50 +++++++++++++++++++++++++++++------
 2 files changed, 61 insertions(+), 10 deletions(-)

diff --git a/Source/Scene/Expression.js b/Source/Scene/Expression.js
index a7a347a22d22..629894b7b827 100644
--- a/Source/Scene/Expression.js
+++ b/Source/Scene/Expression.js
@@ -18,7 +18,7 @@ define([
     "use strict";
 
     var unaryOperators = ['!', '-', '+'];
-    var binaryOperators = ['+', '-', '*', '/', '%', '==', '!=', '>', '>=', '<', '<=', '&&', '||', '!~', '=~'];
+    var binaryOperators = ['+', '-', '*', '/', '%', '===', '==', '!==', '!=', '>', '>=', '<', '<=', '&&', '||', '!~', '=~'];
 
     var variableRegex = /\${(.*?)}/g;
     var backslashRegex = /\\/g;
@@ -531,8 +531,12 @@ define([
                 node.evaluate = node._evaluateDivide;
             } else if (node._value === '%') {
                 node.evaluate = node._evaluateMod;
+            } else if (node._value === '===') {
+                node.evaluate = node._evaluateEqualsStrict;
             } else if (node._value === '==') {
                 node.evaluate = node._evaluateEquals;
+            } else if (node._value === '!==') {
+                node.evaluate = node._evaluateNotEquals;
             } else if (node._value === '!=') {
                 node.evaluate = node._evaluateNotEquals;
             } else if (node._value === '<') {
@@ -834,6 +838,15 @@ define([
         return left % right;
     };
 
+    Node.prototype._evaluateEqualsStrict = function(feature) {
+        var left = this._left.evaluate(feature);
+        var right = this._right.evaluate(feature);
+        if ((right instanceof Color) && (left instanceof Color)) {
+            return Color.equals(left, right);
+        }
+        return left === right;
+    };
+
     Node.prototype._evaluateEquals = function(feature) {
         var left = this._left.evaluate(feature);
         var right = this._right.evaluate(feature);
@@ -1095,9 +1108,13 @@ define([
                 //>>includeEnd('debug');
                 return value + left;
             case ExpressionNodeType.BINARY:
-                // Supported types: ||, &&, ==, !=, <, >, <=, >=, +, -, *, /, %
+                // Supported types: ||, &&, ===, ==, !==, !=, <, >, <=, >=, +, -, *, /, %
                 if (value === '%') {
                     return 'mod(' + left + ', ' + right + ')';
+                } else if (value === '===') {
+                    return '(' + left + ' == ' + right + ')';
+                } else if (value === '!==') {
+                    return '(' + left + ' != ' + right + ')';
                 }
                 return '(' + left + ' ' + value + ' ' + right + ')';
             case ExpressionNodeType.CONDITIONAL:
diff --git a/Specs/Scene/ExpressionSpec.js b/Specs/Scene/ExpressionSpec.js
index 806db406cb67..a4729515b1d8 100644
--- a/Specs/Scene/ExpressionSpec.js
+++ b/Specs/Scene/ExpressionSpec.js
@@ -160,14 +160,6 @@ defineSuite([
             return new Expression('2 & 3');
         }).toThrowDeveloperError();
 
-        expect(function() {
-            return new Expression('2 === 3');
-        }).toThrowDeveloperError();
-
-        expect(function() {
-            return new Expression('2 !== 3');
-        }).toThrowDeveloperError();
-
         expect(function() {
             return new Expression('2 << 3');
         }).toThrowDeveloperError();
@@ -543,6 +535,20 @@ defineSuite([
         expect(expression.evaluate(undefined)).toEqual(2);
     });
 
+    it('evaluates binary equals strict', function() {
+        var expression = new Expression('\'hello\' === \'hello\'');
+        expect(expression.evaluate(undefined)).toEqual(true);
+
+        expression = new Expression('1 === 2');
+        expect(expression.evaluate(undefined)).toEqual(false);
+
+        expression = new Expression('false === true === false');
+        expect(expression.evaluate(undefined)).toEqual(true);
+
+        expression = new Expression('1 === "1"');
+        expect(expression.evaluate(undefined)).toEqual(false);
+    });
+
     it('evaluates binary equals', function() {
         var expression = new Expression('\'hello\' == \'hello\'');
         expect(expression.evaluate(undefined)).toEqual(true);
@@ -552,6 +558,20 @@ defineSuite([
 
         expression = new Expression('false == true == false');
         expect(expression.evaluate(undefined)).toEqual(true);
+
+        expression = new Expression('1 == "1"');
+        expect(expression.evaluate(undefined)).toEqual(true);
+    });
+
+    it('evaluates binary not equals strict', function() {
+        var expression = new Expression('\'hello\' !== \'hello\'');
+        expect(expression.evaluate(undefined)).toEqual(false);
+
+        expression = new Expression('1 !== 2');
+        expect(expression.evaluate(undefined)).toEqual(true);
+
+        expression = new Expression('false !== true !== false');
+        expect(expression.evaluate(undefined)).toEqual(true);
     });
 
     it('evaluates binary not equals', function() {
@@ -1292,6 +1312,13 @@ defineSuite([
         expect(shaderExpression).toEqual(expected);
     });
 
+    it('gets shader expression for binary equals strict', function() {
+        var expression = new Expression('1.0 === 2.0');
+        var shaderExpression = expression.getShaderExpression('', {});
+        var expected = '(1.0 == 2.0)';
+        expect(shaderExpression).toEqual(expected);
+    });
+
     it('gets shader expression for binary equals', function() {
         var expression = new Expression('1.0 == 2.0');
         var shaderExpression = expression.getShaderExpression('', {});
@@ -1299,6 +1326,13 @@ defineSuite([
         expect(shaderExpression).toEqual(expected);
     });
 
+    it('gets shader expression for binary not equals strict', function() {
+        var expression = new Expression('1.0 !== 2.0');
+        var shaderExpression = expression.getShaderExpression('', {});
+        var expected = '(1.0 != 2.0)';
+        expect(shaderExpression).toEqual(expected);
+    });
+
     it('gets shader expression for binary not equals', function() {
         var expression = new Expression('1.0 != 2.0');
         var shaderExpression = expression.getShaderExpression('', {});